These summaries of Koine Greek grammar were created with classical Greek in mind. Where there are differences between classical forms and Koine forms, I have noted the classical forms. (In order to keep each summary down to a single sheet, I did not include dual forms. Duals do not occur in Koine, and are rare in classical Greek. I did include optatives, even though they are rather rare in Koine.)
These summaries are quite terse and dense. If you have studied Greek in the past and need a structured overview to review the essentials of Greek grammar, you may find these charts very helpful. If you are learning Greek for the first time, these charts could be overwhelming, although they might help you (if you learn the way I do) by providing a clear framework which you can gradually fill in with the details.
These summaries assume some background knowledge of grammar, morphology, and accents. Someday I would like to find the time to write up summaries of each of these three topics. The two books that helped me to see the "hidden simplicity" of Greek grammar and captured my interest in linguistics were:
The documents here are in pdf format. Please email me (firstname.lastname@example.org) if you find mistakes. I no longer have convenient access to the Microsoft Windows software with which I created these documents, but I can list any errata. Sorry the files are so large. Also, I couldn't figure out a way to get rid of the empty second page that appears on some of these documents. Perhaps one of these years I will find the time to write these pages up in TeX (or some other free format).
These documents are in the public domain.